wifi: iwlwifi: mvm: fix flushing during quiet CSA

wifi: iwlwifi: mvm: fix flushing during quiet CSA

If, for any reason, we're going to attempt to flush the queues
while quiet CSA is happening, this cannot succeed. This could
be the case if for example mac80211 were to flush after TXing
e.g. a deauth frame due to disconnecting during the CSA.

In this case, drop the frames instead, the firmware won't let
us do any transmissions and may also become unhappy if we're
not going to disconnect quickly enough.

Currently this doesn't happen as mac80211 stops queues, but
we'll want to let mac80211 know not to stop queues for proper
multi-link support during CSA, so we need to handle this case.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240311081938.d5d629f32ea8.I86d9b849d92273542bfc2d9c671b66179e7ebb72@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>